Microphotograph carrier



Nov. 29, i955 E. PETERS 2,72%9@ MICROPHOTOGRAPH CARRIER Filed May 3,1952 3 Sheets-Sheet l i 755 Pz V 755555 7,77

Arr w I Nov. 29, 1955 E, 0, PETERS 2,724,988

MICROPHOTOGRAPH CARRIER 3 Sheets-Sheet 2 Filed May 5, 1952 Num 2Q, '3955a. o. PETER@ 2,724,988

MICROPHOTOGRAPH CARRIER Filed May 3, 1952 3 Sheets5heet 3 7541 C) 73276g "Q" l 7%756 Y m/ d if, x dfn/Z N ff *um y V fym 7% 760O 777 72 7%77a 60 Zw 7725 7005 @ww 726 770 775 United States Patent MICROPHOTOGRAPHCARRIER Edward Otto Peters, La Crosse, Wis., assignor to NorthernEngraving & Manufacturing Co., La Crosse, Wis., a corporation ofWisconsin Application May 3, 1952, Serial No. 285,877 12 Claims. (cl.sti-26) This invention relates to a carrier for moving objects carriedthereby in directions transverse to each other, and more particularly toa microphotograph carrier arranged to selectively position amicrophotograph that is being used with a microphotograph readingmachine.

This microphotograph carrier is for use particularly with amicrophotograph reader of the type described in the copendingapplication of Peters and Brietzke, Serial No. 246,824, filed September15, 1951, now Patent No. 2,700,917, of February l, 1955.

As was pointed out in said copending application, the frames and guidesof microphotograph carriers heretofore made have been constructed veryaccurately, and nearly perfect adjustment of the plane of the carrierwith respect to the axis of the lens of the microphotograph reader wasessential. The cost of such custom work is very great. The invention nthe copending application sought to eliminate the microphotographcarrier as a means for maintaining the microphotograph at a fixeddistance from the focusing lens.

However, the microphotograph when used with the microphotograph readerin the copending application was to be manipulated by hand. An automaticpositioning means for use with the microphotograph reader described insaid copending application is still a desirable machine.

One of the objects of this invention is to provide a microphotographcarrier for use with the microphotograph reader of the type described insaid copending application, which carrier is of simple construction andwhich carrier provides for easy, accurate, and convenient positioning ofthe microphotograph with respect to the microphotograph reader.

Another object of this invention is to provide a microphotograph carrierhaving a simple declutching mechanism for a moving portion thereof whichis driven by a screw member, which declutching mechanism preventsjamming of the carrier when further travel thereof is halted.

A further object of this invention is to provide a microphotographcarrier wherein the microphotograph is clamped onto the carrier andincluding automatic means for releasing the clamped microphotograph.

And still another object of this invention is to provide amicrophotograph carrier for a microphotograph reader, wherein themicrophotograph is clamped onto the carrier, and wherein a portion ofthe microphotograph is clamped between members of the microphotographreader, and including automatic means for simultaneously releasing themicrophotograph clamping member on the carrier and the clamping memberon the reader whereby the microphotograph is completely released.

And still a further object of this invention is to provide amicrophotograph carrier characterized by its novel arrangement of itsparts and its simplicity and inexpensiveness of construction.

Further objects and advantages of this invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize this invention will be pointed out with particularity inthe claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanyingdrawing, in Which Figure 1 is a side view partially in cross section ofa portion of a microphotograph reader having the microphotograph carriermounted thereon.

Figure 2 is a view looking upwardly at the microphotograph carrier withthe housing therefor removed and with portions in cross section, and istaken substantially on line 2 2 of Figure 1.

Figure 3 is a view taken on line 3 3 of Figure 2.

Figure 4 is a fragmentary view looking downward into the portion of thecarrier upon which the microphotograph is positioned, and with parts ofthe housing of the carrier broken away.

Figure 5 is a cross section View taken on line 5 5 of Figure 4.

Figure 6 is a view taken on line 6 6 of Figure 3 showing the gear trainarrangement for the lateral movement drive.

Figure 7 is a fragmentary view similar to Figure 3, showing a portion ofthe mechanism release operatively engaging and displacing a clampingmember of the microphotograph reader so as to release themicrophotograph.

Figure 8 is a View taken on line 8 8 of Figure7.

Figure 9 is an isometric view, with parts broken away, of the releasemechanism for spreading the clamping means for the microphotograph bothon the microphotograph carrier and on the microphotograph reader.

Figure l0 is a fragmentary view similar to Figure 2 showing a modifiedform of the clutch mechanism between the carrier and the lead screw andshowing a manual release mechanism for the microphotograph clampingmeans of the carrier.

Figure 11 is a cross section view taken on line 11 11 of Figure l0.

Referring now to the figures, there is shown in Figure l amicrophotograph reader casing generally indicated at 10, having thereina light source 12, a rellector 14, condenser lenses 16, 18, and 20,contact glass 22, focusing unit 24, focusing knob 26, mirror 28, andviewing screen 30. A clamping member 32 is provided for clamping themicrophotograph card C against the contact glass 22. The microphotographreader is mounted on a stand S.

A microphotograph carriage and drive therefor is enclosed in a casinggenerally indicated at 34, which is mounted on microphotograph readercasing 1t). The casing 34 has a front wall 36, a rear wall 38, a ilattop side 4t), and a bottom wall 42, which wraps around at 44 and 46 tototally enclose the microphotograph carriage and drive mechanismtherefor.

The casing 34 has a mounting flange 48 extending therefrom for mountingthe casing and carrier therein on reader casing 10 by means of bolts 50.Flange 48 has an aperture 52 therein adapted to register with anaperture 54 in reader casing 10, through which passes cooling air forlight source 12.

Referring again to the microphotograph carrier and housing therefor, abearing plate 56 is positioned adjacent the inner side of front wall 36and is secured thereto by means of bolts 58 or the like.

The drive means for the microphotograph carriage includes a lead screw60 having a reduced stud 62 at one end journaled in a bore 64 throughrear Wall 38. The other end of lead screw 60 has a reduced stem 66extending therefrom and journaled in sleeve 68. The extended end 70 ofstem 66 has a control knob '71 mounted thereon and secured thereto bymeans of a set screw 72.

Extending parallel to the lead screw 60 and spaced on opposite sidesthereof are a pair of shafts 72 and 74 of square cross section. Therearward ends of the vshafts 72 and 74 have reduced cylindrical stubs 76and 78 which are journaled in bores in rear wall 3S. The forward ends ofshafts 72 and 7d are provided with similar stubs (not shown) journaledin bores in bearing plate 56.

Shafts 72 and 74 have gears 80 and 82 respectively mounted thereon indriving connection therewith. Gears 81 and S2 are driven by means of agear train comprising fears 8 4, S6, and drive gear S8. Gears 84 and 86are ournaled on studs 90 and 92 extending from bearing plate 56. Thedrive gear SS is formed integrally with sleeve 68. Sleeve 66 has acontrol knob 94 mounted thereon and secured thereto by means of a setscrew 96. The sleeve 68 is rotatably journaled in bore 93 throughbearing plate 56 and front wall 36.

Referring now to the carriage, best shown in Figures 2, 3, 4, and 8, thecarriage includes a mounting plate 166 having a central block 162secured thereto by means of screws 164. There is a central longitudinalbore 196 through said block 162 and through said plate 16d, throughwhich extends lead screw 60.

Mounting plate 16() also provides a pair of apertures 163 in which arejournaled sleeves 116 and 112. The sleeves 116 and 112 each have asquare bore v114 therethrough, adapted to receive the square shafts 72and 74. Mounted on sleeves 11D and 112 are drive rollers 116 and 11S,which are secured thereto by means of set screws 126. The drive rollers116 and 11S are provided with sleeves 117 and 119 of rubber or of someother suitable resilient material. By the means just described, the rollers 116 and 11S are connected in driving relation to shatts 72 and 74through sleeves 116 and 112.

lamping rollers 122 and 12d are associated, respectively, with the driverollers 116 and 11S. Each clamping roller extends parallel to theassociate drive roller and is positioned above the associate driveroller. The clamping rollers are secured to plates 126 and 12S which arepivotally mounted on studs 136 and 132 extending from mounting plate169. r1`he plates 126 and 12S are provided with elongated arcuate slots134 and 136 to accommodate the sleeves 11S and 112 and to permitswinging or" plates 126 and 128. Coil springs 133 and 140 are positionedconcentrically on studs 130 and 132 and are each connected at one end tothe .associate stud and at the other end to the associate plate. Thesecoil springs 138 and 140 serve to bias the clamping rollers toward thedrive rollers in clamping position.

Each clamping roller itself includes a central stem 1-52 secured to theassociate mounting plate. A sleeve 14:4 is

rotatably mounted on the stem 142 and is restrained from ,Y

axial movement thereon by the associate plate at one end and by a snapring or restraint 146 at the other end. Bands 148 of rubber, orotherfsuitable resilient material, are positioned on sleeve 144.

One form of the drive connection between lead screw 6G and the carriageis shown in Figure 10. This drive connection comprises a pair of spacedbores 156 and 152 in central block 102, balls 154 and 156 respectivelyin said bores, and springs S and 166 resiliently biasing the respectiveballs into driving engagement with the threads or" the lead screw 66.The springs 15S and 16) are retained in position by means of plugs 161and 162 threaded into block 102.

The balls 154 and 156 are of greater diameter than the depths of thelead screw groove and therefore a portion of the ball is positioned inthe lead screw groove and the other portion of the ball engages part ofcentra? block 102, in driving engagement therewith. When the lead screwis rotated, and the balls are forced to follow the lead screw groove,such rotation of lead screw results in the carriage travelinglongltudinally of the lead screw.

The top side 46 of the carriage housing 34 is slotted at 163 and 164 toprovide for the projection therethrough of rollers 116 and 11S and theportion of the plates 126 Vand l128 which extend above the rollers 116and 118 and on which the clamping rollers 122 and 124 are mounted. Theseslots are elongated to provide for movement of the carriage along thelength of the lead screw.

in the form of the invention illustrated in Figures 10 and ll, theclamping rollers 122 and 124 are adapted to be manually swung away fromthe drive rollers 116 and 118. The plates 126 and 123 are provided withthumb levers 162 and 164 extending outwardly through slots 166 and 168in the carriage housing. The thumb levers 162 and 164 afford means forswinging the clamping rollers away from the drive rollers. The slotsv166 and 168 are elongated to provide for movementof the carriage alongthe length of lead screw 60.

Means are provided for maintaining t1 e clamping rollers spaced from thedrive rollers. These means in clude resilient latches 170 and 172mounted on block 162. The resilient latches 170 and 172 have shoulders174 and 176 adapted to cooperate with corners 17S and 1S() of the svingable plates 126 and 128, in the manner shown in Figure ll, whereplate 128 is latched in a position where the clamping roller 124 isspaced from the associate drive roller 118. Very little upward force onthumb lever 16-5u is necessary to unlatch the plate 128, whereupon theclamping roller 124 is again biased by spring against the drive roller113.

In the preferred form of the invention shown in Figures l to 9,automatic means are provided for spreading the clamping rollers from thedrive rollers. The drive connection between the lead screw 6@ andcentral block 102 includes a single ball 182 in vertical bore 184 incentral blocl: 162. A toggle member 186 of inverted U-shape is pivotedon a pin 133 extending through bloei; 162. The saddle portion 19d ofU-shaped member 186 is adapted to engage ball 132 and force it intodriving engagement with the threads of lead screw 60.

The U-shaped member 136 has flanges 192 and 194, respectively, adaptedto engage the underside of studs 196 and 198 extending, respectively,from pivotal plates 1"'6 and 12S, Springs 138 and which bias theclamping rollers 1 22 and 124 toward the drive rollers 116 and 11S, alsoserve to cause studs and to engage flanges 192 and 194 to keep theU-shaped member 186 pivoted to a position where the ball 182 ismaintained in driving engagement with the threads of lead screw Whenfurther travel of the carriage along the lead screw 6 0 is halted, thenthe further twisting of the lead screw serves to force the ball to2upwardly over the engaging thread of lead screw 6%, thus forcing theball 132 outwardly of bore 134. The ball 182 engages the saddle surface19) of Ll-shaped member 136 and pivots the U-shaped member 136 about thepivot pin 127:3. The anges 1,92 and 194 engage the studs 196 and 193 andpivot swingable plates 126 and 123 upwardly about the studs 136 andv132. This serves to move the clamping rollers 122 and 124 away fromtheir associate drive rollers 116 and 11S.

Upon further rotation of the lead screw, the ball 183 will again enterthe groove of the lead screw 66, and springs 138 and 11i@ will bias theclamping rollers 1 2 and 12d back toward the drive rollers 116 and 11S,and, simultaneously, through the cooperation of studs 196 and 198 andanges 192 and 194, the U-shaped toggle member 186 will be restored toits original position.

The top side 40 of the carriage housing is provided with an aperture 266through which trie clamping member 32 is adapted to move for clamping aportion of the microphotograph card C against the contact giass 22. Theclamping member 32 is secured to a leaf spring 202 which in turn issecured to the top side 4S by means of a rivet 204.

Upon the clamping rollers 122 and 124 being swnug away from the driverollers so as to release the micro photograph, it is also desired towithdraw the clamping member 32 from glass 2,2. Accordingly, the leafspring 202 is extended at 206 and a hook 208 `is provided at theextended end thereof. The U-shaped toggle member 186 is provided withaflantje 210 adapted to enter the hook 208, as shown in Figure 7. Whenball 182 moves outwardly through bore 184 so as to pivot the U-shapedmember 186 to cause displacement of the clamping rollers` 122 and 124,the ange 210 also moves downward to draw the leaf spring 202 with it andcause the clamping member 32 to be drawn away from contact glass 22.

The lead screw 60 is long enough to accommodate the maximum requiredmovement of the carriage for micropohotograph cards of all sizes. TheU-shaped toggle member 186 is adapted to be actuated, to pivot theclamping rollers 122 and 124 away from the drive rollers 116 and 118,when the movement of the carriage along the lead screw 60 is halted.Stop members are provided which cooperate with portions of the carriageso as to cause the toggle member to be actuated at certain points alongthe length of the lead screw 60. These stop members include a rear stopmember 212 and a front stop member 214. The rear stop member 212 isconcentric with lead screw 60 and is adapted to butt against rear wall38. The front stop member or sleeve 214 is concentric with lead screw 60and is adapted to butt against drive gear 88 on sleeve 68.

The rear stop 212 also serves to space the carriage from the rear wall38 so that the heads of screws 104 are not jammed against rear wall 38.The front stop 214 is of considerable length so as to reduce the lengthof the central block 102. The front stop 214 may be easily andaccurately trimmed to a proper length so that the carriage will behalted at the precise point where pivoting of the toggle member 186results in the proper engagement of flange 210 with hook 208.

The control knob 71, for controlling the movement of the carriage alongthe length of the lead screw 60, and the control knob 94, forcontrolling the movement of the drive rollers 116 and 118, arepositioned concentrically with each other and closely adjacent eachother. This puts all of the necessary controls in a position where theyare easily manipulated by an operator, without the operator having tofumble for the controls.

The controls are also so arranged that they move in directions which areconsistent with the directions in which the microphotograph card Cappears to move upon the viewing screen 30 of the microcard reader. Forexample, when knob 71 is rotated clockwise the carriage moves forwardlyin the direction from rear wall 38 toward the front wall 36 of thecarriage housing 34. As it appears on the screen to the operator, thecard then appears to be moving upwardly across the screen. Sinceclockwise rotation is generally associated with forward progress of mostitems associated with rotatable members, it will be seen that thisclockwise rotation of knob 71 brings about movement of the card in adirection which is generally associated with the direction of rotationof that member.

Similarly when control knob 94 is rotated counterclockwise for thepurpose of going from one page to the next following page, as viewed onthe screen 30, such counterclockwise movement is associated with thegeneral direction of movement obtaining when one turns the pages of abook in sequential order. In going from one page to the next succeedingpage, which pages are printed on a continuous strip, one moves the stripfrom right to left which is generally in a counterclockwise direction.The rotation of knob 94 thus is properly associated with the directionin which the microphotograph card appears to move on the screen of theviewer. It is to be noted that while the counterclockwise rotation ofcontrol knob 94 brings about this result it is necessary that the geartrain including gears 88, 86, 84 and 80 cause the drive rollers torotate in a clockwise direction; and while the card appears to be movingfrom right to left on the screenv 30 of the microphotograph viewer,actually the card is moving from left to right on the carriage, and viceVersa.

It is also pointed out that the complete release of the microphotograph,including the spreading of the clamping rollers 122 and 124 and thedepressing of the clamping member 32, takes place when the carriage isin the forward position. When the carriage is in the forward positionthen the bottom portion of the microphotograph is being viewed on theviewer and usually that is the end of the card. Thus, the release of themicrophotograph takes place at a point where normally one would want torelease the microphotograph, having nished with it and desiring toinsert a new microphotograph on to the carriage.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made therein without departing from theinvention and, therefore, it is intended in the appended claims to coverall such changes' and modications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. In a carriage moving apparatus, a carriage, means mounting saidcarriage for movement only in opposite directions', a lead screwparallel to the directions in which said carriage is adapted to move, ablock carried by said carriage, said block having a bore therethrough,said lead screw extending through said bore in said block, said blockhaving at least one recess therein opening into said bore therethrough,a member positioned in said recess, resilient means in said recessbiasing said member outwardly from said recess into said bore, a portionof said member adapted to enter between threads on said lead screw whileanother portion thereof remains in engagement with said block, so as toestablish an operative connection between said lead screw andl saidblock, the rotation of the lead screw causing said member and therebythe carriage to move longitudinally of said lead screw, and said memberadapted to move out from between the lead screw threads and becomedisengaged therefrom when said carriage is restrained from furthermotion along said lead screw.

2. A positioning apparatus' for moving a flat object carried thereby indirections transverse to each other and a plane parallel to said flatobject, said apparatus comprising a carriage adapted to support theobject, means for moving the carriage in opposite directions, means onthe carriage for selectively moving the object carried thereby inopposite edgewise directions' transverse to the directions in which thecarriage is adapted to move, means engaging opposite sides of said atobject to restrict removal of the object from the carriage, the lattermeans aiording said selective edgewise movement of the object inopposite directions' on the carriage, and means operative upon saidcarriage reaching its limits of movement for rendering said latter meansinoperative, whereby the object carried by said carriage may be removedtherefrom.

3. A positioning apparatus for moving a flat object carried thereby indirections transverse to each other and in a plane parallel to'said flatobject, said apparatus comprising a carriage adapted to support saidobject and movble only in opposite directions, means on said carriagefor moving the object carried thereby in opposite directions transverseto the directions in which the carriage is adapted to move, said lastmeans comprising a plurality of pairs of opposed rollers', each pair ofopposed rollers including one roller mounted to be bodily movable towardand away from the other of said pair of rollers, each pair of rollersadapted to be selectively spaced apart to permit introductiontherebetween of an object and adapted to be moved together to engageopposite sides of said'object, means for rotating one of each pair ofrollers simultaneously to etect movement of said object selectively inopposite directions, and means operative upon said carriage reaching itslimits of movement to spread apart the rollers of each of said pairs ofrollers, whereby the object gripped therebetween may be released.

4. A positioning apparatus for moving a at object carried thereby indirections transverse to each other and in a plane parallel to said atobject, said apparatus comprising a lead screw rotatably journaled atvits ends in a frame, a pair of shafts extending paraliel to and onopposite sides of said lead screw and rotatably journaled at their endsin said frame, a carriage connected to said lead screw for movementalong the length thereof as said lead screw is rotated, a pair of driverollers slidably and non-rotatably mounted on said pair of shafts andmovable with said carriage, a irst control knob for rotating said leadscrew, a second control knob coaxial with said rst control knob andpositioned closely adjacent thereto for rotating said pair of shafts anddrive rollers thereon, and said connection between the carriage and thelead screw including a member engaging said carriage and movable intoand ont of the groove between threads on said screw, said member ridingup over a screw thread as the screw is turned so as to render said connection inoperative upon the movement of said carriage along said leadscrew being halted.

5. A positioning apparatus for moving a hat object carried thereby indirections transverse to each other and in a plane parallel to said atobject, said apparatus comprising a carriage movable in oppositedirections, a pair of drive rollers movable with said carriage andadapted to move an object carried thereby in opposite directionstransverse to the directions in which said carriage is adapted to move,a clamping roller associated with .each drive roller extending parallelthereto and mounted on said carriage for swinging toward and away fromthe associate drive roller respectively to grip or release an objecttherebetween, means biasing each clamping roller toward its associatedrive roller, and means for selectively maintaining said clamping rollerin a position spaced from its associate drive roller.

6. A positioning apparatus for moving a at object carried thereby indirections transverse to each other and in a plane parallel to said flatobject, said apparatus comprising a carriage movable only in oppositedirections, a pair of drive rollers movable with said carriage andadapted to move an object carried thereby in opposite directionstransverse to the directions in which said carriage is adapted to move,a clamping roller associated f clamping roller toward its associatedrive roller, means r for selectively swinging each clamping roller awayfrom its associate drive roller, and means for maintaining said clampingroller spaced from said drive roller.

7. A positioning apparatus for moving a flat object carried thereby indirections transverse to each other and in a plane parallel to said atobject, said apparatus comprising a lead screw rotatably journaled atits' ends in -a frame, a pair of shafts extending parallel to and onopposite sides of said lead screw and rotatably journaled at their endsin said frame, a carriage adapted to move along the length of said leadscrew, a pair of drive rollers slidably and non-rotatably mounted onsaid pair of shafts and movable with said carriage, a clamp rollerassociated with each drive roller and extending parallel thereto, eachclamping roller being mounted on said carriage for swinging toward andaway from its associate drive roller, a member engaging said carriageand releasably engaging the threads of said lead screw and adapted tomove out of engagement with said threads upon the movement of saidcarriage along said lead screw being halted while said lead screwcontinues to be turned, a togglemember adapted to be actuated Yby saidmember as the member is moved out of engagement from said screw threads,to swing the clamp rollers away from their associate drive rollers andto maintain said rollers spaced apart until said member again restoresoperative connection between said lead screw and said carriage by againentering between threads of said lead screw.

8. A positioning apparatus for moving a flat object carried thereby indirections transverse to each other and in a plane parallel to said atobject, said apparatus comprising a lead screw rotatably journaled atits ends in a frame, a pair of shafts extending parallel to and onopposite sides of said lead screw and rotatably jour naled at their endsin said frame, a carriage adapted to move along the length of said leadscrew, a pair of drive rollers slidably and non-rotatably mounted onsaid pair of shafts and movable with said carriage, a clamp rollerassociated with each drive roller and extending parallel thereto, eachclamp roller being mounted on said carriage for Swinging toward and awayfrom its associate drive roller, a member engaging said carriage andreleasably engaging the threads of said lead screw and adapted to moveout of engagement with said threads upon the movement of said carriagealong said lead screw being halted while said lead screw continues to beturned, a toggle member adapted to be actuated by said member as themember is moved out of engage ment from said screw threads, to swing theclamp rollers away from their associate drive rollers and to maintainsaid rollers spaced apart until said member again restores operativeconnection between said lead screw and said carriage by again enteringbetween threads of said lead screw, and means' biasing each clampingroller toward its associate drive roller, said biasing means beingoperative to bias said member toward a position for operative connectionof the carriage to the lead screw.

9. A positioning apparatus for moving a flat object carried thereby indirections transverse to each other and in a plane parallel to said atobject, Said apparatus comprising a lead screw rotatably journaled atits ends in a frame, a pair of shafts extending parallel to and onopposite sides of said lead screw and rotatably journaled at their endsin said frame, a carriage releasably connected by a member movable intoand out of said lead screw groove for movement along the length thereoicas said lead screw is rotated, a pair of drive rollers slidably andnon-rotatably mounted on said pair of shafts and movable with saidcarriage, a clamp roller associated with each drive roller and extendingparallel thereto, each clamp roller being mounted on said carriage forswinging toward and away from its associate drive roller, means biasingsaid clamp rollers toward their associate drive rollers, and meansbiasing said member toward a position to operatively connect saidcarriage and lead screw.

10. In combination, a microphotograph viewer including an objectiveglass, and a clamping member positioned opposite said objective glassand mounted for movement toward and away from said glass, said clampingmember being operative to clamp a microphotograph against said objectiveglass; anda positioning apparatus for moving a microphotograph carriedthereby in directions transverse to each other, said positioningapparatus comprising a carriage movable selectively -in a rst pair ofopposite directions, .and means on said carriage for moving saidmicrophotograph selectively in a second pair of opposite directionstransverse to said iirst pair of directions, members on said carriageswingable toward and away from each other respectively for gripping andreleasing said microphotograph, and means operative upon said carriagereaching its limit of movement in one direction for simultaneouslymoving apart the members which grip the microphotograph, and for movingsaid clamping member away from said objective glass so as to release themicrophotograph which is clamped therebetween.

1l. in combination, a microphotograph viewer including an objectiveglass, and a clamping member positioned opposite said objective glassand mounted for movement toward and away from said glass, said clampingmember being operative to clamp a microphotograph against said objectiveglass; and a positioning apparatus for moving a microphotograph carriedthereby in a rst pair of directions, said positioning apparatuscomprising a carriage, means for selectively moving said carriage inopposite directions, two pairs of rollers movable with said carriage andpositioned on opposite sides of said objective glass and clampingmember, each pair of rollers including a drive roller and an associatedclamping roller swingable toward and away from said drive roller, saiddrive rollers adapted to support a microphotograph thereon, saidclamping rollers and drive rollers adapted to cooperate to grip amicrophotograph therebetween, said clamping member clamping a portion ofthe microphotograph between said pairs of rollers against said objectiveglass, means for rotating said drive rollers to move saidmicrophotograph selectively in a pair of opposite directions transverseto said rst pair of directions, and means operative upon said carriagereaching its limit of movement in one direction for simultaneouslymoving the clamping rollers away from the drive rollers and for movingthe clamping member away from said objective glass, so as to release themierophotograph therebetween.

l2. A positioning apparatus for moving a flat object carried thereby indirections transverse to each other and in a plane parallel to said flatobject, said apparatus comprising a carriage adapted to support saidobject and movable only in opposite directions, a lead screw parallel tothe directions in which said carriage is adapted to move and operativelyconnected thereto to move said carriage in said directions, means on thecarriage for moving the objects supported thereon in opposite directionstransverse to the direction in which the carriage is adapted to move,and the connection between the carriage and lead screw including a blockcarried by said carriage, said block having a bore therethrough, saidlead screw extending through said bore in said block, said block havingat least one recess therein opening into said bore therethrough, amember positioned in said recess, resilient means in said recess biasingsaid member outwardly from said recess into said bore, and a portion ofsaid member adapted to enter between threads on said lead screw whileanother portion thereof remains in engagement with said block, so as toestablish an operative connection between said lead screw and saidblock.

References Cited in the tile of this patent UNITED STATES PATENTS1,530,173 Harris Mar. 17, 1925 2,260,551 Boni Oct. 28, 1941 2,292,825Dilks Aug. 11, 1942 2,341,378 Hopkins Feb. 8, 1944 2,369,980 ReyniersFeb. 20, 1945 2,441,168 Richardson May l1, 1948 2,511,646 Marmour June13, 1950 FOREIGN PATENTS 13,467 Great Britain June 16, 1903

